Physical Optics ( Interference)

To be Winner, you have to Like, Share Facebook Page otherwise we won't count your answer.
Facebook Like and Share:

Before Choosing the Best Answer Questionaire have to follow ;
1) There should be minimum 5 Answers of different users.
2) Choose the Answer which is unique, simple, described and not copied from google.
3) If the answers are same, view the date and time who have answered first.